Spelunking Ear Drum Dwellings

As artists we are accustomed to making connections between seemingly disparate themes and images to generate new ideas and forms. Synesthesia when used as a perceptual mode or even as a concept brings attention to the multi-sensory way that we can perceive our external and internal worlds.
According to David M. Eagleman, Ph.D., a Neuroscientist working out of Baylor College of Medicine in Houston Texas, their is still dispute on what exactly goes on in the brain to cause synesthesia. From a neurological view their are two schools of thought. One is that the brain of a synesthete, compared to a "normal" brain, is equipped with a greater concentration of the neural pathways that connect disparate sensory regions in the brain. This would cause a greater flow of information between the brains different regions, resulting in joined synesthetic perceptions. The other theory, the one favored by Eagleman, is that all brains have the same basic wiring and concentration of that wiring. Eagleman argues that it is a matter of exciters and inhibitors that either promote the cross pollination of information or restrict it. Eagleman gives examples of people who do not normally experience synesthesia, but who under certain conditions do. For example, fatigue can actually heighten ones ability to experience synesthesia, also the influence of LSD and DMT are known to incite joined perceptual sensations in the brain. The fact that these "normal" people are capable of synesthetic perception under uninhibited states points to Eagleman's favored theory of exiters and inhibitors (Eagleman).
In my experience with synesthesia it always occurs in a state in between dreaming and waking. It is a state where my mind is loose enough to perceive the visuals that are presented to me by the sound, be it ambient or musical, and my mind is conscious enough to recognize and recall the images and sensations. I have known that my brain operates this way for years but I had forgotten the key which is attention. I was reminded of this after reading Jeffrey M Schwartz, M.D. book, The Mind & the Brain, Neuroplasticity and the Power of Mental Force. In Chapter 10 of his book Schwartz speaks about the power of attention in directing what we see. "Brain activity in a ciruit that is physiologically dedicated to a particular task is markedly amplified by the mental act of focusing attention on the feature that the circuit is hard-wired to to process. In addition, during the directing of such selective attention, the prefrontal cortex is activated. As we saw in Chapter 9, this is also the brain region implicated in volition or, as we are seeing, in directing and focusing attention's beam"(Schwartz). This is an extremely useful insight, that by anticipating a certain mode of perception, in my case synesthesia in sleep/waking states, the circuits already in place in my brain are already activated and primed for a synesthetic experience.